Right now we have a hack in ve.test.utils.js that reregisters the core versions of HeadingNode and PreformattedNode to ensure MWHeadingNode and MWPreformattedNode aren't used, because using them would break the VE core tests when run in VE-MW.
This is horrible, because it makes us unable to test specific behavior in the MW nodes. For instance, https://gerrit.wikimedia.org/r/#/c/162310/3 fails its own tests because those tests use HeadingNode rather than MWHeadingNode, even though the tests in question were clearly designed to use MWHeadingNode.
We should come up with a way that MW nodes can be not registered for code tests, but be registered for MW tests.
Version: unspecified
Severity: enhancement